Carbon fiber has a unique physical and chemical properties, widely used in aerospace, automotive, chemical, infrastructure, military, sports, energy, textile and other fields. However, the carbon-like graphite structure makes the surface chemically inert, the interface is low, the interface wetting property and the high temperature oxidation resistance are poor, and the chemical group with high reactivity is lacking, which makes the carbon fiber and other base material can not form between Effective interface coupling, the interface strength decreased, which seriously affect its mechanical properties. In addition, with the dye molecules between the low chemical bonding, making it difficult to dye, resulting in the development of carbon fiber products tone is too simple, it is difficult to meet the consumer demand for fashion.

The existing methods for achieving carbon fiber fabric coloring are: weaving about 50% of dyeable yarns such as glass fiber, polyester, copper, aramid, etc., but the mechanical properties of carbon fiber fabrics are correspondingly reduced; Apple announced A patent US7790637B2 changes the appearance color of the carbon fiber fabric by adding an additional "scrim". The University of Manchester has recently developed a new electrochromic resin that can be used as a carbon fiber prepreg to produce stable, reversible color changes under the applied electric field.

Nevertheless, maintaining the high mechanical properties of the carbon fiber fabric while achieving its direct coloring is still a problem that scientists need to overcome. Recently, Professor Wang Shimin of Hubei University and Professor Xu Weilin of Wuhan Textile University have developed an effective and easy-to-use carbon fiber fabric coloring method, which is not only color adjustable but also has excellent washing resistance. This study has been published in the International Journal of Materials Science Topical Journal "ACSNano" (FacileandEffectiveColorationofDye-InertCarbonFiberFabricswithTunableColorsandExcellentLaunderingDurability). According to the introduction, the study mainly from the bionic structure of the idea of ​​color, the use of ALD (atomic layer deposition) technology in the carbon fiber / fabric surface construction of different sizes of amorphous TiO2 film, to achieve the carbon fiber and fabric coloring.

The structural color is a series of colorful biological colors produced by the physical effects of selective reflection, dispersion, scattering, interference, diffraction and transmission on visible light in a series of microscopic structures with special optical scales. The color of the structure has no pollution, no fading, high saturation brightness, no rainbow color effect of the coloring mechanism also makes it have other dyeing technology can not match the technical advantages and broad application prospects. This provides a new idea for the ecological coloring of carbon fibers.

Nature of the structure of the color

Methods for constructing structural colors include sol-gel method, self-assembly, holographic lithography, inkjet printing, anodic oxidation, electrophoretic deposition, electrospinning and atomic layer deposition (ALD). ALD is a special chemical vapor deposition technology, due to self-limiting surface chemical reaction characteristics, atomic layer deposition technology has excellent shape retention, uniformity of large area growth and precise sub-monolayer film thickness controllable characteristics. Nano-level controllable chemical bonding growth and excellent shape-preserving properties make it both resistant to service characteristics, and easy to operate, high stability, free from the size and shape of the matrix material can control the composition of the film at the atomic level structure and Thickness, wide applicability, no pollution to the surrounding environment.

However, since the surface of the carbon fiber fabric is mainly a chemically inert sp2 bond, it is difficult to initiate the ALD reaction on the CFF. In this study, the use of carbon fiber surface defects and oxygen-containing functional groups (such as-OH and -COOH), can effectively start the growth characteristics of TiO2 film, first introduced TIP (titanium tetraisopropoxide), through the carbon fiber surface-OH or - (CH3) 2 on the surface of the carbon fiber and the introduction of H2O with -OCH (CH3) 2 to form a single layer of TiO2 film and exposed-OH, after each step, In addition to the remaining substances. By repeating the above ALD cycle number, the desired thickness of the TiO2 film can be precisely adjusted.

Around the carbon fiber around the TiO2 film

By controlling the thickness of amorphous TiO2 film, this study realizes the successful preparation of the three primary colors red, yellow and blue, and can change the thickness of the surface of the carbon fiber fabric by the combination of the three primary colors to obtain other different colors. And the resulting TiO2 film excellent washing performance, can withstand 50 times the washing. This result is the direction for achieving the ecological coloring of carbon fibers and their fabrics.